Motion picture piracy is a cause of substantial revenue loss to the motion picture industry. Illegally copied motion pictures can be a significant contributing factor to revenue loss for motion picture studios. Such illegal copies of a motion picture are typically made using a sophisticated telecine apparatus or filmed during projection using a video camera. Even the questionable quality of motion pictures pirated in this fashion does not prevent them from broad distribution in the “black market”, especially in some overseas markets, and on the Internet. As video cameras improve in imaging quality and become smaller and more capable, the threat of illegal copying activity becomes more menacing to motion picture providers. While it may not be possible to completely eliminate theft by copying, it can be advantageous to provide forensic techniques that help to pinpoint where an illegal copy of a motion picture was made, whether obtained using a video camera device or copied directly from a print film using a telecine or other scanning apparatus.
It is known to provide a distinct symbol or watermark to an original still image as a means of image or copy identification, such as in order to authenticate a copy. As examples, U.S. Pat. No. 5,875,249 entitled “Invisible Image Watermark For Image Verification filed by Mintzer et al. on Jan. 8, 1997; U.S. Pat. No. 6,031,914 entitled Method and Apparatus Embedding Data, Including Watermarks, In Human Perceptible Images, filed by Tewfik et al. on Aug. 27, 1997; U.S. Pat. No. 5,912,972 entitled Method and Apparatus For Embedded Authentication Information Within Digital Data filed by Barton on Jun. 15, 1999; and U.S. Pat. No. 5,949,885 entitled Method For Protecting Content Using Watermarking filed by Leighton on Aug. 29, 1997, disclose methods of applying a perceptually invisible watermark to image data as verification of authorship or ownership or as evidence that an image has not been altered. Advanced steganographic or “hidden content” techniques used for embedding watermarks and other information content within images are also disclosed in commonly assigned U.S. Pat. No. 6,044,156 entitled Method for Generating An Improved Carrier For Use In An Image Data Embedding Application, filed by Honsinger et al. on Apr. 28, 1997; U.S. Pat. No. 5,850,481, entitled Steganographic System filed by Rhoads on May 8, 1995; and U.S. Pat. No. 6,353,672 entitled Steganographic Using Dynamic Codes filed by Rhoads on Mar. 8, 2000. Embedded watermarks formed using such techniques, can provide various types of encoded message information, for example, a string of bits.
Watermarking schemes, such as those disclosed in the patents listed above, can be employed to add an identifying watermark within the recorded image area of each copy of a motion picture. Proper deployment of such techniques can provide a watermark encoding that is imperceptible to the viewer's eye but can be detected when analyzing a pirated copy of a motion picture. Such watermarks are typically made to be robust, that is, able to withstand various “attacks” that can remove or alter the watermark.
To provide accurate tracking of a motion picture watermark, it is necessary to uniquely identify the distribution path of the print. In fact, for even better precision, there can be advantages in providing multiple watermarks in a single copy of a motion picture, so that each copy of a motion picture contains at least one individual length or segment of film having a unique, trackable watermark. In this way, even an individual segment of film of an illegally copied motion picture could be analyzed, its watermark detected, and its processing and distribution history tracked with precision. In order to provide this type of tracking capability, the processing and distribution history for each copy of a motion picture and/or a segment of film must be stored in some accessible fashion, such as in a database, and the watermark must be coupled, that is, associated in some way, to the specific stored information about a segment of film or motion picture. This type of tracking can be used, for example, to provide forensic data and evidence that can be used to identify and prosecute those making an illegal copy of a motion picture.
In order to appreciate the difficulty involved in tracking the many copies of a motion picture, it is instructive to understand the conventional process by which a motion picture is manufactured, processed, and provided to a theater or other exhibitor. Referring to FIG. 1, there is shown an overview of the prior art process for producing and distributing a motion picture. A media manufacturer 20 initially manufactures film stock known as print film in the form of a large web of un-imaged print film. The web of un-imaged print film is then slit to produce multiple strips of un-imaged print film 22 which are then wrapped about core 24 to produce multiple rolls 26 of un-imaged print film 22. Such un-imaged print film rolls 26 are typically 6000 feet in length; however, they can be any other convenient length. As un-imaged print film 22 is fabricated by media manufacturer 20 information may be exposed onto the un-imaged print film 22 such as product code, strip number, roll and part number, date or other information. This information is typically exposed on an edge of un-imaged print film 22, outside of an area of un-imaged print film 22 that is to receive scene content. Such information is not accessible until after the un-image print film 22 is processed by film processor 50.
When a studio 30 releases a motion picture for distribution, a master copy 32 of the motion picture is provided to a printing lab 34. At printing lab 34, a printing apparatus 36, such as a contact printer, is used to imprint an image of master copy 32 onto one or more rolls 26 of un-imaged print film 22. Printing apparatus 36 has an exposure head 38 that exposes images from master copy 32 onto un-imaged print film 22 to form an exposed print film 46 that is wound to form an imaged print film reel 48. Master copy 32 may be fed in a continuous loop or fed from a source reel 42 to a take-up reel 44.
Imaged print film reel 48 is taken from printing apparatus 36 and provided to film processor 50 for development using a conventional chemical process that routes exposed print film 46 through a sequence of baths 52 such as a developer bath 52a, a bleach bath 52b, and a fixer bath 52c. After this process, exposed print film 46 is dried to become a developed print film 54. Alternatively, exposed print film 46 can be processed in other ways such as using thermal processing methods to form developed print film 54. Developed print film 54 is then packaged, for example, by mounting developed print film 54 on reel cores 56, becoming film reels 58 having a typical length of 2000 feet. Typically a motion picture is made up of six to eight film reels 58 that vary in length. However, the number and length of film reels 58 used for a feature film can vary depending on the length of the motion picture.
Film reels 58 are then sent to a distributor 64, also known as a film exchange, who adds reel sides 60 that snap into reel cores 56 to provide protection and integrity to the developed print film 54. Reel sides 60 can alternatively be added at printing lab 34. Film exchange 64 assembles the appropriate film reels 58 to form a package comprising the entire motion picture for distribution to exhibitors 66. Exhibitors 66 typically provide the necessary splicing or handling required to combine the provided reels to display the motion picture.
It must be observed that the sequence shown in FIG. 1 is deliberately simplified for the sake of description and allows a number of variations in actual practice, but should be adequate for an overall understanding of key processes from film manufacture through distribution. Film packaging, for example, may be varied, depending on whether cores 24, reel cores 56, or other support structures are most appropriate. Processes illustrated at printing lab 34 such as printing and developing can all be performed at one location or performed at different locations. The roles of printing lab 34, developer 50 and film exchange 64 can overlap or be combined in many different ways than described or shown in FIG. 1.
With respect to FIG. 1, it can be seen that it is possible to use a watermark to uniquely identify each developed print film 54 in a way that the watermark can be extracted from an illegal copy of a motion picture recorded on the developed print film 54. However, to use such a watermark to identify the origin of illegal copies, the distribution path of the developed print film 54 bearing the watermark must be known. This requires each developed print film 54 be tracked throughout its subsequent processing and distribution. However, as is shown in FIG. 1, the complexity of the film printing, developing and distribution process presents significant traceability challenges. What is needed is a method and system that are capable of building an association between a detected watermark and tracking of distribution information for that motion picture. What is also needed is a method and system that are capable of accurately maintaining and updating tracking information for each motion picture throughout each stage of film processing and distribution. Such a method and system should be relatively inexpensive, require little labor, and be unobtrusive and difficult to circumvent.
It will be appreciated that there is some capability, using conventional edge-coding techniques that expose information outside the image area, to provide an identifier that can only be used for identification after un-imaged print film 22 moves through exposure and development, but this would be inconvenient and obtrusive during distribution due to pakaging. Therefore there is no ready access to the edge coded information.
Thus, what is needed are methods and systems for tracking the movement of watermarked film that are conveniently applied at all stages of producing and distributing a motion picture.